Rotary circuit-interrupter



H. 0. PUTT.

' ROTARY CIRCUIT INTERRUPTER.

APPLICATION FILED FEB. 5, 1918.

1,341,020, Patented May 25, 1920.

UNITED STATES? HARLIE OGDEN FUTT, 0F ELKIdAR/l, INDIANA.

ROTARY CIRCUIT-INTERRUPTER.

Specification of Letters Patent.

Patented May 25, 1920.

Application filed February 5, 1918. Serial No. 215,442.

To all whom it may concern:

Be it known that I, I-IARLIE OGDEN PUTT, a citizen of the United States,residing at Elkhart, in the county of Elkhart and State of Indiana, haveinvented a new and useful Rotary Circuit-Interrupter, of which thefollowing is a specification.

In all mechanical circuit interrupters, the function of closing thecontact points is accomplished by spring tension or by cam actionapplied to an oscillating contact which is normally open, while theopening or separation of the contact points is accomplishedin the rotarytype--by causing the contact arm to strike a cam surface, or, in therevolving cam type, by causing the cam to strike the contact arm or byholding the contact arm normally open by means of a stiff spring.

In either of the two above types of interrupter, the function of closingthe contacts by spring tension only, results in imperfect contact athigh magneto speeds unless excessively stiff spring tension is employed,in which case the contact points, cam surfaces, etc., are rapidly worn.Also at high speeds the spring tension is somewhat neutralized bycentrifugal force, in the case of the rotary type, and when the camreleases the contact arm permitting contacts to close, the arm reboundsor chatters, causing a break, or a series of breaks in the generatedelectrical wave or current.

At high speeds the force of impact of the cam and contact arm tends tocause contact points to open too far, thereby detracting from efficiencyand life of contact points and other wearing parts. At low speeds theaction is more or less slow, whereas a quick break or separation of thecontact points is desirable.

The object of my invention is to provide a rotary'circuit interrupterwhich has none of these defects, thereby attaining higher efficiency andlonger life.

The closing of the contact points, in my invention, is positivelysecured or accomplished by cam action, while the opening or breaking ofcircuit is accomplished by spring tension and centrifugal force actingon a contact arm.

The spring tension is just sufiicient to quickly open contact points atlow magneto speeds, While at high magneto speeds this action isaccelerated by centrifugal force acting on the contact arm. in additionto the normal spring tension, thereby securing an automatic adjustmentof contact arm tension at any magneto speeds. Breaking of tension springwould not render interrupter inoperative, as the centrifugal action oncontact arm would act to open the contact, irrespective of springtension, in fact the interrupter may be operated with this tensionspring entirely eliminated, but better results are secured at lowmagneto speeds by the use of this spring. I

Rebound, or chattering of contact points is entirely eliminated andpositive contact secured with a minimum of spring tension andconsequently less wear, thereby adding to efficiency and longer life ofthe mechanism.

The degree or distance of separation of the contact points is uniform atall speeds. There is no hammering or pounding of contact points.

The construction is extremely simple, accessible and efficient, and canbe manufactured cheaply.

In the accompanying drawings, Figure 1 is a section on line 1 1 of Fig.2, showing interrupter and cam; and Fig. 2 is a sectional view of Fig. 1on line 22 of Fig. 1, showing manner of attachment or assembly tomagneto armature shaft.

Like characters designate like parts throughout the several views.

Referring to the drawings, C in Fig. 1 is the cam of cylindrical form,which is capable of being oscillated, or may be rigidly secured o themagneto. Two cam-releasing and cam-engaging portion such as suitabledepressions or slots, C and C are provided diametrically opposite in oneend of cam cylinder, or when only one break per revolution of armatureis desired, then only one slot or depression is employed. The width ofthese cam-releasing and cam-engagin portions determines the degree thatthe contacts remain open, and can be readily cut to meet anyrequirement.

The inner surface corners of the elements and C are to be slightlybeveled. D is the contact arm pivoted or journaled at E which carries atension spring G secured by screw F. The opposite end of spring G issecured to post H by means of screw F The tension of this springoperates to open contact points. K is a fiber block or other suitablewear-resisting material inserted in and rigidly fastened to arm D.

.L is a flat spring screwed or riveted to arm D at one extremity andcarrying a contact point P at the other extremity. Q, is the insulatedbracket which carries adjustable contact screw M which is locked inposition by locknut O and loekscrew N. This bracket is rigidly attachedto interrupter disk J by means of insulated screw R and collector stemor screw S. Screw S is in electrical connection with bracket Q. T is theadjustable stop screw which screws into post H and is locked in positionby locknut T and controls throw of contact arm D. V is a retainingspring having one extremity fastened to post id, and the other bearingagainst contact arm D at its fulcrum point. This spring merely holds armD on its journal, and can be swung around permitting arm D to be removedfrom its journal by removing screws 1* and F The interrupter disk orbody J is preferably provided with a taper boss, which fits intoarmature shaft and is held in place by means of collector stem or screwS, which has a taper fit in insulated bracket Q. The design of arm D issuch as to cause centrifugal force to act in conjunction with spring Gin direct proportion to the speed of rota tion.

The operation is as follows: At slow magneto speeds the fiber block Kengages cam surface causing contact points to close against action ofspring hen fiber block K reaches slot in cam, spring it throws arm Doutward thereby opening contact points, and they remain open while blockK passes over slot in cam to opposite sector, when block K again engagescam surface and thereby closes contact points, spring L actingresiliently on contact points and arm D,

The adjustment of contact screw M and stop screw T is such as to permitcontact points to open the required distance when fiber block K is notengaged by cam G.

The suddenness or rapidity of break is determined by the abruptness ofthe cam slot, where the fiber block K leaves it, but a slight bevel willnot detract from electrical efficiency, and will prevent block Ksticking or catching on cam when rotated in reverse direction. As thespeed of rotation increases, the centrifugal action on arm D operateswith spring G to cause a correspondingly quick break, while the camsurfaces force a positive make or closing of contact points withoutchatter or rebound, and by virtue of the resilient action of spring Lall undue wear is eliminated from contact points and fiber block K andother wearing parts.

lVhat I claim is:

1. In a rotary circuit interrupter, the combination of a hollowcylindrical casing having one or more cam slots therein, contactcarrying members mounted within said eas ing, one of said members havingan operative contact with the inner surface of the cylindrical casing tonormally maintain the contact points in closed relation, said memberbeing pivotally mounted to permit of its being swung outward bycentrifugal force during the period determined by the aforesaid camslots whereby the rapidity of the break of contact is proportional tothe effect of centrifugal force acting on the pivoted contact arm.

2. In combination with the apparatus disclosed in claim 1, a springoperatively connecting the contact carrying members and having a tensionjust suliicient to quickly open contact points at low magneto speedsindependent of centrifugal force.

8. In a rotary circuit interrupter, the combination of a cylindricalmember having one or mbre cam slots, a collector stem, an interrupterdisk mounted to but insulated from the stem, a contact arm pivotallymounted to the disk and carrying a fiber block to engage the cam slots,means for limiting the pivotal movement of the contact arm said meansincluding an adjustable stop screw, an insulated bracket mounted to theinterrupter disk and carrying an adj ustable contact member, an opposingspring contact member carried by the contact arm, and means to open thecircuit at low magneto speeds resiliently connecting the contact arm andthe above-mentioned means for limiting the pivotal movement of thecontact arm whereby to close the circuit by cam action and to open it bycentrifugal force and spring tension.

4. In a rotary circuit interrupter, the combination of a cylindricalmember having opposite cam slots, a collector stem, an interrupter diskmounted to and insulated from the stem, a contact arm pivotally mountedto the disk, a post carried by the interrupter disk, an adjustable stopscrew carried by the post and adapted to limit the centrifugal movementof the contact arm, an insulated bracket mounted to the interrupterdisk, an adjustable contact member carried by said bracket, an opposedresiliently mounted contact member said member being carried by thecontact arm, and a fiat spring connecting the contact arm with the postcarried by the interrupter disk said spring being adapted to reinforcethe centrifugal action in throwing the contact arm outward on enteringcam slots, substantially as and for the purposes described.

5. In a rotary circuit interrupter, the combination of a hollowcylindrical casing having one or more cam slots therein, a pivotedcontact-carrying member having an operative slidable engagement with theinner surface of the aforesaid cylindrical casing, means for limitingthe pivotal movement of said member, a second contact carrying ele ment,a spring having one end rigidly mounted and having the other end aiiixedto the contact carrying member first mentioned, said spring beingresiliently ten sioned to open the contacts by its resilient action atlow magneto speeds while admitting of a more rapid operation bycentrifugal force at high speeds, substantially as described.

6. In combination with the apparatus described in claim 5, means foradjusting the pivotal movement of the first mentioned pivoted contactcarrying member.

7. In a rotary circuit interrupter, the combination of a hollowcylindrical casing having one or more cam-releasing and cam-engagingportions, contact-carrying means mounted within the aforesaid casing andin operative contact with its inner surface to normally maintain thecontacts closed, said means being operable by centrifugal force to openand close the contacts during the period it moves past the cam-releasingand cam-engaging portions of the cylindrical casing, whereby thequickness of break of contact is controlled by and proportional to thecentrifugal force acting on the pivoted contact arm.

8. In combination with the apparatus disclosed in claim 7, resilientmeans in operative engagement with the contact-carrying means andadjusted to quickly open the contacts at low magneto speeds independentof centrifugal force.

9. In a rotary circuit interrupter, the combination of a hollowcylindrical cam having one or more cam-releasing and cam engagingportions to admit of a pivoted contact member swinging outwardly andsubsequently being swung inwardly by the aforesaid cam, a pivotedcontact member having an operative slidable engagement with the innersurface of the aforesaid hollow cylindrical cam, means for limiting thepivotal movement of said contact member, resilient means controlling theoperation of the contact member to a limited degree and arranged to openthe contacts by its resilient action at low magneto speeds and admittingof a more rapid operation of the contact element by centrifugal force athigh speeds, for the purposes described.

10. In combination with the apparatus described in claim 9, means foradjustably regulating the operation of the pivoted contact element.

11. In a rotary circuit interrupter, means carrying an electricalcontact member, means carrying a cooperating electrical contact member,a member carried by said last mentioned means adapted to slidably engagea cam to positively maintain the electrical contacts in closed relationfor definite periods in the operation of the device, the said cammember, and resilient means attached to the means carrying thecooperating electrical contact member and tensioned to afford thedesired control of the opening of the contact points and the breaking ofthe circuit at low magneto speeds.

HARLIE OGDEN PUTT.

